The availability of drugs in the workplace and, in the general population, is pervasive. Employers and others, such as government agencies, general contractors, sports groups and, particularly transportation companies, often utilize drug screening, out of necessity, for both conditions of employment and to ensure safety in the workplace. However, it is impractical to have doctors perform each drug screening on site on a routine basis and also employing a doctor for such tasks is prohibitively expensive.
As a result the various commercial devices have been developed for drug screening in the field (on site) by employers and others which provide near instantaneous test results when liquid samples are collected in such devices. For example, see U.S. Pat. No. 5,403,551 entitled “Assaying Device and Container for In Field Analysis of a Specimen and Later Shipment of the Unadulterated Specimen” issued to Galloway, U.S. Pat. Nos. 6,805,838; 6,805,837; and 6,497,843 issued to Tydings, all entitled “Assaying Device and Method for In-Field Urinalysis”. Other patents for such devices included U.S. Pat. No. 6,726,879 issued to Ng et al. See also U.S. Pat. No. 6,140,136 issued to Lee teaching a similar device.
Along with cups the prior art teaches the use of test cassettes, where the test strips lay in a horizontal plane secured to a test bed and the technician places a few drops of a specimen onto the sample area of the individual test strips in the cassette. These test cassettes have reagent test strips attached thereto that change color in the presence of certain chemicals, in this case drugs.
In other embodiments test cassettes can be manufactured so that the ends of the test strips can be submerged into the specimen collection container holding a liquid the specimen. These cassettes are often referred to as dippers due to the step, during use, of submerging them in a liquid specimen; see for example U.S. Pat. No. 7,222,547 issued to Alley.
In general the above referenced devices are adapted to bring a small portion of a liquid specimen, such as a urine sample which is collected from an individual, into contact with test strips containing reagents which are responsive to the presence of drugs, such as amphetamines, cocaine, morphine, PCP, THC and/or their metabolites. Typically such reagents include, but are not limited to, colloidal gold coated sheep polyclonal anti-amphetamine, mouse monoclonal anti-benzoyl ecgonine, polyclonal rabbit anti-morphine-3 glucuronide, mouse monoclonal anti-cannabinoid or mouse monoclonal anti-phencyclidine, appropriate drug or drug analog conjugates, and immobilized antisera.
Typically the test strips have a top portion with a selected reagent and an absorbent sample pad at the bottom. Inside the strip are an absorbent membrane and a reaction membrane in communication with the absorbent pad at the bottom. When the absorbent sample pad contacts urine, the urine will wick through the conjugate pad to the reagent (disposed on the reaction membrane) resulting in a positive or negative indication on the surface of the strip; the indication may be one line for positive and two lines for a negative or vice versa, e.g., for large molecule tests such as hormone test, one line is negative, two line is positive. Such test strips are commercially available from companies who have FDA clearance for the same, see FDA web site www.FDA.gov for the names of such companies.
In the past problems have been experienced with flooding of the test strips by the urine samples. Devices such as taught in U.S. Pat. No. 5,403,551 issued to Galloway and also in other patents, use separate compartments to limit the amount of liquid specimen which comes in contact with the test strips. As another example, see U.S. Pat. No. 6,726,879 issued to Ng et al. which uses separate chambers to limit the amount of specimen that comes in contact with the test strips, the patent pointing out that it is highly desirable to limit the contact of a urine sample with the reagent portion of the strips. To this end U.S. Pat. No. 6,397,620 issued to Lee et al., as well as some of the Tyding's patents referenced, supra, employ a vertical surface in a urine collection cup having a wicking membrane disposed thereon so that the wicking membrane conveys urine from the bottom of the cup to the absorbent sample pads of the test strips located at the top of the vertical surface via capillary action. Such arrangements are adapted to avoid flooding the test strip with the urine sample, in that case, which can invalidate the test results.
Problems also exist in situations where an inadequate amount of liquid specimen is absorbed by the test strip. Too little and too much of the specimen can affect the reliability of test results.
Products like the versatile device of this invention, currently in the market place, require the devices to be dipped in the specimen and submerged for a specific time specified by the manufacturer. This dwell time ensures the specimen saturates the wicking pad. The novel device, of the present invention, requires only a quick dip (a second or two) to activate the test, wherefore no dwell time is required to obtain an accurate test.
When specimen volume is limited, products currently available are hard to use. In the novel device of the instant invention a tester can use transfer pipet by adding drops of specimen into an opening in the device to activate the testing with reliable results.
Various prior art devices of the types described above can be viewed at http://www.rapidxams.com, illustrating drug check cups, cassettes and dip or dipper units.
It is an object of the present invention to provide a novel drug testing device which eliminates flooding of the test strips when a carrier containing the strips is submerged in a liquid specimen for either temporarily or for an extended period of time, the submersion time not being critical.
Another object is a provision of a novel drug testing device that ensures more accurate and positive test results when using conventional drug test strips because the novel device requires no required (or specified) submersion period.
In addition the novel device includes a well below its lower opening that serves as a “reservoir” to store enough specimen for a reliable test even after a quick dip in a liquid specimen which feature expedites and simplifies testing making the novel device user friendly.
Still another object is the provision of an improved drug testing device that is economical to construct without sacrificing its drug testing reliability.
Another object is the provision of a construction that insures an adequate sample of a liquid specimen engages each test strip in the device to provide reliable testing without flooding the test strip.
It is also an object to provide an improved drug testing device which can provide reliable test results with limited quantities of a liquid specimen.
It is a general object of the present invention to provide an assaying device which is capable of easily collecting and testing a liquid specimen, such as urine, while avoiding many of the problems experienced by prior art devices now available in the market place.
It is also an object to prove a novel device is constructed of transparent material which provides an improved viewing area of the test strips and which also allows multiple tests to be performed on a single strip (e.g., 2 to 3 test can be performed on a single test strip).